C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

Gas Gauge Problem

Thread Tools
 
Search this Thread
 
Old Aug 12, 2019 | 07:12 AM
  #1  
tmirisola's Avatar
tmirisola
Thread Starter
Burning Brakes
 
Joined: Nov 2014
Posts: 920
Likes: 190
From: Stoneham, MA
Default Gas Gauge Problem

At 26k Miles my 1999 C5 Gas Gauge will only show 3/4 filled when I know the tank is filled. Any suggestions please
Reply
Old Aug 12, 2019 | 07:16 AM
  #2  
Vetteman Jack's Avatar
Vetteman Jack
Administrator
Supporting Lifetime
Veteran: Navy
St. Jude 20 Year Donor
25 Year Member
Veteran: Reserves
 
Joined: Mar 2001
Posts: 367,986
Likes: 24,715
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Default

Run a bottle of Techron Concentrate through the next couple of tanks of gas and see if that helps clear up the gas gauge problem. Sulfur deposits on the sending unit can cause an erratic gauge.

And moved to C5 Tech.
Reply
Old Aug 12, 2019 | 07:16 AM
  #3  
dmd1998's Avatar
dmd1998
Intermediate
 
Joined: Aug 2019
Posts: 46
Likes: 1
From: Voluntown, CT
Default

I have read there are additives you can put in your tank that clean up the fuel sending unit called techron.. Never used it but have heard many good things. I would try that before anything.
Reply
Old Aug 12, 2019 | 04:29 PM
  #4  
laurent_zo6's Avatar
laurent_zo6
Melting Slicks
10 Year Member
 
Joined: Aug 2013
Posts: 2,491
Likes: 315
St. Jude Donor '15-'16-'17-'18-'19-'20-'21-'22
Default

It's a common problem with Corvette C5. Plenty of posts on the subject. As mentioned above, a bottle of Techron seems to help. Just make sure to add it to the tank when it is about a quarter full so it can travel between both tanks. Don't drive for a a day or so to let the Techron do its work.
Reply
Old Aug 13, 2019 | 09:35 AM
  #5  
Josephu's Avatar
Josephu
Pro
 
Joined: Sep 2017
Posts: 675
Likes: 195
From: Green Oak Township, Michigan
Default

Always have mine over half full so that the Techron flows into the passenger tank. Im not sure if the fuel is siphoned into the drivers tank, or if it goes directly to the engine. Maybe someone can chime in on this.
Reply
Old Aug 13, 2019 | 10:25 AM
  #6  
feeder82's Avatar
feeder82
Safety Car
20 Year Member
Liked
Loved
Top Answer: 1
 
Joined: Mar 2005
Posts: 3,753
Likes: 1,212
From: Wisconsin
Default

Make sure you try the Techron concentrate+ not the fuel system cleaner
Reply
Old Aug 13, 2019 | 12:54 PM
  #7  
laurent_zo6's Avatar
laurent_zo6
Melting Slicks
10 Year Member
 
Joined: Aug 2013
Posts: 2,491
Likes: 315
St. Jude Donor '15-'16-'17-'18-'19-'20-'21-'22
Default

Originally Posted by Josephu
Always have mine over half full so that the Techron flows into the passenger tank. Im not sure if the fuel is siphoned into the drivers tank, or if it goes directly to the engine. Maybe someone can chime in on this.
A CF member posted this a while ago regarding fuel tanks info:
Attached Images
File Type: pdf
Gas tanks info.pdf (82.3 KB, 83 views)
Reply

Get notified of new replies

To Gas Gauge Problem





All times are GMT -4. The time now is 05:48 PM.

story-0
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-1
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-2
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-3
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-4
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-5
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-6
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-7
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-8
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-9
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE